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Camless Internal Combustion and the Digital Age (hackaday.com)
szczys writes: The internal combustion engine is amazing, and it continues to evolve. Carburetors gave way to fuel injection, and a computer now monitors all kinds of sensors to ensure these engines operate at peak efficiency. But there is one thing that has remained largely unchanged: the cam shaft. This is a device responsible for mechanically timing the operation of the cylinders. It's possible to build an engine that uses digitally controlled actuators instead of a camshaft to decide when each cylinder should fire. These exist as prototypes — we have the technology, so why aren't we building with it? The answer is that change is hard, and as with the carburetor it could take an outside force (in that case mandatory efficiency benchmarks) to get automobile manufacturers to wager a bet on new technology.
You may be right, but the technology might be useful elsewhere. Also, if they choose the right kind of actuator they might be able to reduce or eliminate the spring tension, which would make it easier. Also also, don't forget that the camshaft robs the engine of plenty of power on its own, so the electronically actuated ones don't have as far to go as we might think.
I didn't think anyone still built interference engines, either, but apparently at least as of two years ago, a lot of smaller engines used interference designs. With that said, AFAIK, there's no technical reason that government safety standards couldn't mandate that electronic valve timing be used exclusively with non-interference designs. That would probably go a long way towards ridding the world of interference engines, at least in the long run, which would be IMO a good thing.
For that matter, the main reason that valves are designed the way they are designed is that they have to be operated mechanically using simple levers. With an electronically controlled valve, at least in principle, there's no reason the valve couldn't be built in such a way that it either:
Any of those would eliminate the risk of the head colliding with the valves, and that last one could potentially also allow the ECU to individually adjust how much the valves open based on temperature, throttle, etc. much more precisely than any purely mechanical design, which might be beneficial in terms of fuel efficiency, noise, etc., or at least might allow them to eliminate external hardware that regulates airflow, thus reducing the overall cost of the engine.
That said, I am not an engine designer, so this is mostly speculation.
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They're still using cams. The pneumatic side is for closing the valves rather than using springs. Switching from heavy, inertia laden springs allows to penumatic closure allows for higher RPMs and more aggressive cam profiles.